Occurrence and Photochemical Degradation of Estrogenic Steroids in Coastal Seawater

雌激素和相关的合成类固醇，如避孕药和激素替代疗法药物中使用的类固醇，已被证明存在于水生环境中，主要是由于废水处理厂的去除效率低下。这些化合物的浓度虽然很低（低于ng至几ng/L），但足以诱导雌激素反应并改变野生生物的正常繁殖和发育。在雌激素类化合物中，人工合成的避孕类固醇，如17 α-乙炔基炔雌醇（EE 2），被认为是最强的内分泌干扰物。即使浓度极低（如0.1纳克/升），也能导致雄鱼雌性化。马萨诸塞州的布扎德湾与人口密集城市附近的许多其他沿海环境一样，接收雨水径流和废水处理设施的废水（例如，新贝德福德和费尔黑文WTP将其废水直接排入布扎德湾）。这导致许多不同类别的污染物直接输入，包括干扰内分泌的雌激素进入布扎德湾，在这项研究中，马萨诸塞州大学达特茅斯分校的研究人员将以布扎德湾作为靠近人口密集城市的沿海环境的代表，研究沿海海水中雌激素的来源、运输、浓度变化、微生物和光化学转化。 首席调查员？初步研究表明，尖网河口海水中EE 2等雌激素类类固醇的浓度超过5 ng/L，对该湾鱼类和其他野生动物有显著影响。 本研究的主要目的是：（1）研究布扎德湾海水中雌酮、17 β-雌二醇、雌三醇、雌激素酯2（EE 2）和美雌醇（mestranol）的来源和浓度的季节变化;（2）评价布扎德湾中雌激素的微生物和光化学降解速率;（3）测定天然溶解性有机物、过渡金属Fe、溶解氧和光照波长对光化学降解的影响;（4）鉴定雌激素类固醇光降解的中间产物，并评估其雌激素活性。就更广泛的影响而言，这项研究将提高公众对近岸环境中雌激素化合物的存在及其对海洋海岸生态系统影响的认识。本计画将透过将海洋水生生物光化学实验技术带入教室，整合进教学计画中。通过演示，实验室练习，实地考察和独立的研究项目，学生将能够应用他们在海洋和化学课程中学到的知识，努力理解物理化学的众所周知的定律不仅适用于实验室，而且还调节自然界中发生的反应过程。研究生、本科生和高中生都将参加这项研究。还将努力让少数民族学生参与拟议的研究，并为他们未来在科学相关领域的职业生涯做好准备。该项目还将加强达特茅斯的马萨诸塞州大学的研究和教育基础设施。

Estrogenic hormones and related synthetic steroids, such as those used in contraceptive pills and hormone replacement therapy drugs, have been shown to be present in the aquatic environment, mainly as a result of inefficient removal in wastewater-treatment plants (WTPs). The concentrations of the compounds, although very low (sub-ng to a few ng/L), are sufficient to induce estrogenic responses and alter the normal reproduction and development of wildlife organisms. Of estrogenic compounds, synthetic contraceptive steroid, such as 17á-ethinylestradiol (EE2), are found to be the most potent endocrine disruptor. It can cause feminization of male fish even at extremely low concentrations (e.g. 0.1 ng/L). The Buzzards Bay in Massachusetts, like many other coastal environments near densely populated cities, receives stormwater runoff and effluents from wastewater treatment facility (for example, New Bedford and Fairhaven WTPs discharge their effluents directly into Buzzards Bay). This leads to direct input of many different classes of pollutants, including endocrine-disrupting estrogens into Buzzards Bay.In this study, researchers at the University of Massachusetts at Dartmouth will use Buzzards Bay as a representative of coastal environments close to densely populated cities to study the sources, transportation, concentration variation, microbial and photochemical transformation of estrogenic hormones in coastal seawater. The principal investigator?s preliminary study has shown that the concentration of EE2 and other estrogenic steroids were over 5 ng/L in Acushnet river estuary seawater, at which they may significantly affect fish and other wildlife in the Bay. The main objectives of this proposed research are to: (1) examine the sources and seasonal concentration variation of estrogenic hormones: estrone, 17â-estradiol, estriol, EE2 and mestranol in Buzzards Bay seawater; (2) assess the microbial and photochemical degradation rate of estrogenic hormones in Buzzards Bay; (3) determine the influences of natural dissolved organic matter, transition metal Fe, dissolved oxygen and irradiation wavelength on the photochemical degradation; (4) identify the intermediate products of photodegradation of estrogenic steroids and evaluate their estrogenic activity.In terms of broader impacts, this study will raise public awareness of the presence of estrogenic compounds in the nearshore environment and their impact to marine coastal ecosystems. The proposed project will be integrated into a teaching program by bringing the experimental techniques of marine aquatic photochemistry into the classroom. Through demonstrations, laboratory exercises, field studies and independent research projects, students will be able to apply what they have learned in their marine and chemistry courses, in an effort to understand that the well-known laws of physical chemistry not only apply in the laboratory but also regulate the course of reactions taking place in nature. Both graduate, undergraduate and high school students will participate in this research. Efforts will also be made to involve minority students in the proposed research and prepare them for a future career in a science related field. This project will also enhance infrastructure for research and education at the University of Massachusetts, Dartmouth.